I'm coming from a need to output a site-global parameter in a variable as field output.
We can write lots of handlers as suggested in #730752: Expose site info (site name, site base url) as field but this does not feel smart to me.

We might write a little "variable_get" handler - not too difficult and meybe fine for now.

But we can do better and use the token system (you know, drupal-tokens, not views field tokens).
Variables will soon come in for free with #1434826: Make Drupal variables accessible with data browser in rules.

Besides the "site" token well-known from rules we might have row entities and maybe context as token objects.

Architectural feedback for this?